Tamron SP AF17-35/2.8-4 Di LD Aspherical (IF) Review

The Tamron SP AF17-35/2.8-4 Di LD Aspherical (IF) is a fast, general
purpose lens for both digital and film cameras. On a film camera the 17-35 mm range covers
a lot of applications from landscapes and photojournalism to travel and environmental
portraits. On a typical APS-C digital camera, such as the Canon EOS 20D, it has the same
field of view as a 27-56mm lens would on a full frame 35mm camera. This is a range
typically used for both landscape work and photojournalism (street shooting).

Tamron SP AF17-35/2.8-4 Di LD Aspherical (IF) is a Tamron "Di" lens. Di
lenses designed with digital SLRs in mind and Tamron say that they have higher resolution,
better control of flare and ghosting, less light fall-off and lower chromatic aberration
than earlier designs.

Note that the Tamron SP AF17-35/2.8-4 Di LD Aspherical (IF) Review has full frame 35mm
coverage. Just because it's designated as a "Di" (digitally optimized) lens
doesn't mean that it has reduced frame coverage like, for example, the Canon EF-S series
lenses. You can use this lens on an APS-C sensor SLR (e.g. Canon EOS 20D) or on a full
frame 35mm film body.

Tamron SP AF17-35/2.8-4 Di LD
Aspherical (IF) Specifications

Model Number

A05

Lens Construction (Groups/Elements)

11/14

Angle of View

104 - 63 degrees (full frame 35mm)

Focal Length

17mm to 35mm

Maximum Aperture

f2.8-f4

Diaphragm Blade Number

7

Minimum Aperture

f22 (17mm) - f/32 (35mm)

Minimum Focus

0.3m (entire zoom range)

Macro Mag. Ratio

1:5.4 (at 35mm)

Filter Diameter

77mm

Weight

440g

Diameter x Length

83.2mm x 86.5mm

Accessories

Lens hood

Mount

Canon, Minolta-D, Nikon-D, Pentax

The lens solidly constructed with a low reflectivity black finish and a rubberized zoom
control. It comes with a "petal" style detachable lenshood. The barrel material
appears to be plastic.

The zoom cannot be locked, but I saw no "creep" at any focal length setting,
even with the lens pointing vertically up or down.

Focus can be switched between AF and MF with a small switch on the left, near the lens
mount. Manual focus is smooth with about a 90 degree rotation of the rubberized focus ring
from 0.3m to infinity. There are no depth of field scales and no IR focus identification
mark. It's marked with focal lengths of 17mm (maximum aperture f2.8), 20mm (maximum
aperture f3.2), 24mm (maximum aperture f3.5), 28mm (maximum aperture f3.5) and 35mm
(maximum aperture f4)

Focus speed is pretty good. It takes the Tamron SP AF17-35/2.8-4 Di LD Aspherical(IF)
about 0.5 seconds to go from infinity to 0.3m. Focusing isn't silent but it's not really
noisy and certainly not a problem.

The lens extends slightly (less than 1cm)when zoomed, but does not change length on
focusing (it's internal focus - IF) and the front of the barrel does not rotate when the
lens is zoomed or focused. However the focus ring does spin during autofocus, so keep your
hands away from it.

Tamron SP AF17-35/2.8-4 Di LD Aspherical (IF) Optical Construction

The Tamron SP AF17-35/2.8-4 Di LD Aspherical (IF) uses two types of special optical
elements as shown above. LD (low dispersion) glass is used to minimize chromatic
aberration and aspherical elements are used to minimize aberrations like spherical
aberration which become troublesome in fast wideangle lenses.

The lens has a close focus distance of 0.3m which gives a maximum magnification of
1:5.4 at 35mm.